Since the reverse shape memory effect(RSME) was reported in a CuZnAl alloy, further study has been done on the mechanism of this phenomenon and reported that it occurs by the bainitic transformation. But the present authors revealed in the previous work that the RSME in a B2 CuZnAl alloy is not caused by the shear process involved in the bainitic transformation and also that the RSME takes place as the remaining ${alpha}^{prime}{_2}$ phase, which is two-step transformed strain induced martensite, is newly transformed into ${alpha}$ phase. In order to provide further evidence in supporting the facts, thus, more detailed investigations have been carried out in a $DO_3$ CuZnAl alloy.